/*
 * Copyright (C) 2015 The Guava Authors
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.google.common.collect.testing.testers;

import static com.google.common.collect.testing.features.CollectionSize.ZERO;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_KEYS;
import static com.google.common.collect.testing.features.MapFeature.ALLOWS_NULL_VALUES;
import static com.google.common.collect.testing.features.MapFeature.SUPPORTS_PUT;

import com.google.common.annotations.GwtCompatible;
import com.google.common.collect.testing.AbstractMapTester;
import com.google.common.collect.testing.features.CollectionSize;
import com.google.common.collect.testing.features.MapFeature;

import java.util.Map.Entry;
import java.util.concurrent.ConcurrentMap;

import org.junit.Ignore;

/**
 * A generic JUnit test which tests {@code putIfAbsent} operations on a concurrent map. Can't be
 * invoked directly; please see {@link
 * com.google.common.collect.testing.ConcurrentMapTestSuiteBuilder}.
 *
 * @author Louis Wasserman
 */
@GwtCompatible
@Ignore // Affects only Android test runner, which respects JUnit 4 annotations on JUnit 3 tests.
public class ConcurrentMapPutIfAbsentTester<K, V> extends AbstractMapTester<K, V>
{
    @Override
    protected ConcurrentMap<K, V> getMap()
    {
        return (ConcurrentMap<K, V>) super.getMap();
    }

    @MapFeature.Require(SUPPORTS_PUT)
    public void testPutIfAbsent_supportedAbsent()
    {
        assertNull("putIfAbsent(notPresent, value) should return null", putIfAbsent(e3()));
        expectAdded(e3());
    }

    @MapFeature.Require(SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testPutIfAbsent_supportedPresent()
    {
        assertEquals(
                "putIfAbsent(present, value) should return existing value",
                v0(),
                getMap().putIfAbsent(k0(), v3()));
        expectUnchanged();
    }

    @MapFeature.Require(absent = SUPPORTS_PUT)
    public void testPutIfAbsent_unsupportedAbsent()
    {
        try
        {
            putIfAbsent(e3());
            fail("putIfAbsent(notPresent, value) should throw");
        }
        catch (UnsupportedOperationException expected)
        {
        }
        expectUnchanged();
        expectMissing(e3());
    }

    @MapFeature.Require(absent = SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testPutIfAbsent_unsupportedPresentExistingValue()
    {
        try
        {
            assertEquals(
                    "putIfAbsent(present, existingValue) should return present or throw",
                    v0(),
                    putIfAbsent(e0()));
        }
        catch (UnsupportedOperationException tolerated)
        {
        }
        expectUnchanged();
    }

    @MapFeature.Require(absent = SUPPORTS_PUT)
    @CollectionSize.Require(absent = ZERO)
    public void testPutIfAbsent_unsupportedPresentDifferentValue()
    {
        try
        {
            getMap().putIfAbsent(k0(), v3());
        }
        catch (UnsupportedOperationException tolerated)
        {
        }
        expectUnchanged();
    }

    @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_KEYS)
    public void testPutIfAbsent_nullKeyUnsupported()
    {
        try
        {
            getMap().putIfAbsent(null, v3());
            fail("putIfAbsent(null, value) should throw");
        }
        catch (NullPointerException expected)
        {
        }
        expectUnchanged();
        expectNullKeyMissingWhenNullKeysUnsupported(
                "Should not contain null key after unsupported putIfAbsent(null, value)");
    }

    @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
    public void testPutIfAbsent_nullValueUnsupported()
    {
        try
        {
            getMap().putIfAbsent(k3(), null);
            fail("putIfAbsent(key, null) should throw");
        }
        catch (NullPointerException expected)
        {
        }
        expectUnchanged();
        expectNullValueMissingWhenNullValuesUnsupported(
                "Should not contain null value after unsupported put(key, null)");
    }

    @MapFeature.Require(value = SUPPORTS_PUT, absent = ALLOWS_NULL_VALUES)
    @CollectionSize.Require(absent = ZERO)
    public void testPutIfAbsent_putWithNullValueUnsupported()
    {
        try
        {
            getMap().putIfAbsent(k0(), null);
        }
        catch (NullPointerException tolerated)
        {
        }
        expectUnchanged();
        expectNullValueMissingWhenNullValuesUnsupported(
                "Should not contain null after unsupported putIfAbsent(present, null)");
    }

    private V putIfAbsent(Entry<K, V> entry)
    {
        return getMap().putIfAbsent(entry.getKey(), entry.getValue());
    }
}
